A method is known from German Patent No. DE 103 23 567 A1 for modulating the torque transmitted by a vehicle clutch, in particular during the engaging of the clutch when driving off. In this method, the torque is modulated depending on a variable derived only from the speed of rotation of the clutch plate in order to specify a method for modulating the torque transmitted by the clutch at which chatter vibrations can be controlled more precisely.
A method is known from German Patent Application Publication No. 10 2011 086 579.9 for reducing chatter vibrations in a motor vehicle drivetrain having a drive unit, a vehicle transmission and an automated friction clutch. In order for the activation of the clutch actuator to take place in a phase-variable manner depending on the vibration frequency that occurs, and with a signal that is as smooth as possible without stimulating higher frequency components, the following steps are carried out: (1) multiplying a present signal value of a signal that describes a sine function over time with a starting frequency, with the present signal value of the signal of the transmission input speed to a present value Sine_product, and multiplying a present signal value of a signal that describes a cosine function over time with a starting frequency, with the present signal value of the signal of the transmission input speed to a present value Cosine_product; (2) calculating a sliding average over the present value Sine_product as well as all values Sine_product, which, starting from the present value Sine_product, have been obtained over a period of the starting frequency and assigned to a value Sine_portion, and calculating a sliding average over the present value Cosine_product as well as all values Cosine_product, which, starting from the present value Cosine_product, have been obtained over a period of the starting frequency and assigned to a value Cosine_portion; (3) ascertaining the amplitude from the values Sine_portion and Cosine_portion; (4) ascertaining the phase shift between the signal of the transmission input speed and the cosine function; (5) ascertaining a signal which represents the chatter vibration from the amplitude and the phase shift; (6) ascertaining a value of a phase shift of the signal, which represents the chatter vibration, where the value is chosen so that when there is a phase shift of the signal representing the chatter vibration, it produces a control signal to the clutch actuating system at this value, which reduces the chatter vibration.